Loader bucket



y 8, 1968 E. B. WAGNER 3,385,460

LOADER BUCKET Filed June 27. 1966 2 Sheets-Sheet 1 INVENTOR. EDDIE B. WAGNER May 28, 1968 Filed June 27. 1966- a a. WAGNER LOADER BUCKET 2 Sheets-Sheet 2 INVENTOR. EDDIE B. WAGNER flitorhey United States Patent 3,385,460 LOADER BUCKET Eddie B. Wagner, Portland, 0reg., assignor to Wagner Mining Scoop, Inc., Portland, 0reg., a corporation of Oregon Filed June 27, 1966, Ser. No. 560,742 1 Claim. (Cl. 214-778) ABSTRACT OF THE DISCLOSURE In the present construction the bucket structure is provided with wheels which roll on the ground during forward movement of the vehicle in digging and scooping and support the bucket at an effective digging angle. When the bucket has scooped itself full of material, it is broken out of the pile by tilting it back to erect position before raising the boom. The wheels support the front end of the boom and provide a ground fulcrum for the bucket during this operation so that a powerful uplift can be exerted on the lip of the bucket without tending to lift the other end of the vehicle. After the bucket has broken out of the pile, the boom is capable of lifting the load.

This invention relates to improvements in the bucket structure for a loader vehicle.

A loader is a vehicle having a forwardly extending boom carrying a pivotally mounted bucket arranged for digging and scooping, carrying and dumping. As loader buckets become larger, certain problems arise making conventional forms of construction unsuitable. For example, with a very large bucket it becomes dilficult or impossible after scooping the bucket full to break the lip of the bucket up out of a pile of heavy material.

In conventional loaders the lowermost position of the boom is arranged to hold the bottom, or back, of the bucket elevated above the ground so as to incline the lip downward at' an effective digging angle. The bucket is broken out of the pile by raising the boom. The lever arm from the lip of the bucket back to the wheels of the vehicle is so long that with a large bucket the opposite end of the vehicle lifts up instead of the bucket.

Another problem arises in dumping a large bucket. A bottom portion of the bucket is conventionally pivotally mounted on the boom whereby when the bucket is tilted to an effective dumping angle the lip of the bucket is depressed a considerable distance below the high end of the boom. In order to dump at a predetenmined height as, for example, into a truck, the boom must be raised higher with a large bucket for the lip of the bucket to clear the load in the truck. However, in raising the boom higher, the arcuate path of the boom tip carries the bucket back toward the end of the vehicle so that the bucket then cannot cast its load into the truck. Merely lengthening the boom does not provide an acceptable answer to this problem because a lengthened boom would make it more diliicut to break the lip of the bucket up out of a pile of material in scooping.

General objects of the invention are, therefore, to provide an improved bucket structure for large buckets, to improve the ability of the bucket to break up through a pile of heavy material after digging and scooping and to provide an improved dumping arrangement so that the bucket will dump with its lip in a higher position without raising the boom to an excessive angle.

More particular objects are to provide means to fulcrum the bucket on the ground while breaking the lip of the bucket up out of a pile of material, to provide wheels on the bucket structure for such purpose and to provide an improved dumping mechanism which will hold the lip of the bucket at a high elevation in dumping.

High level dumping of the bucket is accomplished by pivoting the bucket on a cradle at a point near the lip of the bucket instead of at the bottom of the bucket. This arrangement places the lip of the bucket even higher than the upper end of the boom whereby the boom does not have to be raised to an excessively high angle. With the boom remaining at a medium elevation, the bucket can then cast its load farther forward into a truck or other elevated receptacle than with conventional forms of construction.

The invention will be better understood and the foregoing and other objects and advantages will become apparent from the following description of the preferred embodiment of the invention illustrated in the accompanying drawings. Various changes may be made in the details of construction and arrangement of parts and certain features may be used without others. All such modifications within the scope of the appended claim are included in the invention.

In the drawings:

FIGURE 1 is a side elevation view of a loader vehicle embodying the principles of the invention, with the bucket in carrying position;

FIGURE 2 is a fragmentary side elevation view showing the bucket in digging and scooping position; and

FIGURE 3 is a view similar to FIGURE 2, showng the dumping position in full lines and showing the conventional dumping position in broken lines.

The loader vehicle illustrated by way of example in FIG- URE 1 has two body sections 10 and 11 pivotally connected together at 12 for steering by means of a pair of convention-a1 steering cylinders 13 as well understood by persons skilled in the art. Body section 10 containing the engine is supported by a pair of wheels 14 on opposite sides of the vehicle. For the purpose of the present description these w'heels will be referred to as rear wheels since the movement of the vehicle in scooping will be referred to as a forward movement. Body section 11 is supported on two pairs of wheels 15 and 16 on opposite sides of the vehicle and wheels 15 will be referred to as front wheels. The invention is applicable to other types of vehicles, however.

Body section 11 carries a pivotally mounted boom 20 which may be raised and lowered by a pair of conventional boom lift cylinders 19. Pivotally mounted at 21 on the front end of the boom is a bucket supporting cradle 22 which carries a large loader bucket 23. A lower portion of cradle 22 adjacent its pivotal support 21 is equipped with brackets 24 having bearings for ground wheels 25 on opposite sides of the cradle and bucket.

Bucket 23 is pivotally mounted on a hinge on the forward end of cradle 22. At a short distance from the hinge 30 is the bucket digging and scooping lip 31. Extending back from lip 31 the bucket has a flat front wall 32. This wall must be inclined downward at a small angle for digging and scooping as shown in FIGURE 2 and it must be inclined downward at a :much greater angle of approximately 45 for dumping as shown in FIGURE 3. Wheels 25 and lip 31 support the cradle and bucket at an effective digging angle on the ground as shown in FIG- URE 2. Hinge 30 extends along the outside of front wall 32 and is preferably located closer to lip 31 than to the bottom 33.

The bucket is normally latched in fixed position nested in cradle 22 by a pair of pivotal latch levers 35 on the rear end of the cradle having hooked ends which engage pins 36 on the back side of the bucket. These latch levers are spring actuated to latched position and are actuated to unlatched position by pistons and piston rods 37 in small single acting cylinders 38.

Cradle'22 and bucket 23 are erected from scooping position in FIGURE 2 to carrying position in FIGURE 1 by a piston and piston rod 4!) in a double acting hydraulic cylinder 41. Cylinder 41 is pivotally mounted on body section 11 at 42. The front end of this piston rod 40 is pivotally connected to a rod 43 on cradle 22. In the present bucket the ends of rod 43 are utilized to support the latch levers 35 for pivotal movement.

When latches 35 are released, the bucket may be pivoted for dumping by a pair of double acting hydraulic dump cylinders 45, one on each side of the bucket as shown in FIGURE 3. Cylinders 45 are pivotally connected to the bottom of cradle 22 at 46 and have pistons and piston I'Ods 47 extending upward for connection to the bucket near its upper edge at 48. Cylinders 45 are controlled by a manual valve lever which may also include means for controlling latch cylinders 38.

In digging and scooping, boom 20 is lowered and cradle 22 is tilted forward by piston rods 40 until the bucket is supported on the ground on wheels 25 and lip edge 31 with the bucket latched to the cradle as shown in FIGURE 2. Digging thrust is exerted by boom 20 and piston rod 40 as the vehicle is driven forward.

When the bucket has scooped itself full, it is erected to its FIGURE 1 position by retracting piston rod 40 without raising boom 20. This rotation of the bucket lifts the lip 31 to break the bucket out of the pile with the wheels 25 providing a fulcrum on the ground. The weight of material bearing down on front wall 32 of the bucket in its FIGURE 2 position acts on a maximum lever arm equal to the distance from lip 31 to the wheels 25. This length of lever arm is insufiicient to lift rear wheels 14 off the ground.

In a conventional loader without wheels 25, the bucket is broken out by lifting the boom 20 which makes the lever arm extend from lip 31 back to wheels 15. Heavy material acting on such a long lever arm holds the boom down and causes the wheels 14 to lift off the ground.

Once the bucket has been broken out of the pile and erected on its wheels 25 as shown in FIGURE 1, the boom 20 is capable of lifting the full bucket to carrying and dumping positions. Conventional dumping position is shown in broken lines in FIGURE 3 wherein the bucket is rotated about pivot 21 to place its flat front wall on a 45 slope as indicated at 320. This places the lip at position 310 a relatively short distance above the ground as indicated by dimension A. In order to raise the lip higher to dump .into a truck or other elevated receptacle, the boom 20 would have to be raised to a steep angle which would bring the bucket over the wheels 15 and prevent it from dumping into the truck.

The present construction overcomes this difiiculty by dumping on the hinge axis 30 which places the lip 31 at the far greater height B and also as a horizontal distance C farther in front of the wheels 15. Thus, with these improvements, a large bucket may be employed to advantage and the operational difficulties experienced with conventional construction are overcome.

Having now described my invention and in what manner the same may be used, what I claim as new and desire to protect by Letters Patent is:

1. In a loader vehicle, a boom, a cradle pivotally connected with said boom, ground engaging wheels on said cradle on an axis spaced forward from the axis of said pivotal boom connection, a bucket in said cradle, said bucket being pivotally connected with said cradle by hinge means outside the front wall of the bucket at an intermediate point between the lip of the bucket and the bottom of the bucket, upright dumping cylinders connected between the bottom of said cradle and upper edge portions of said bucket on opposite sides of the bucket, and a cylinder and piston rod unit connected between the vehicle and said cradle for tilting said cradle and bucket forward to scooping position and for erecting said cradle and bucket to carrying position, said wheels providing the fulcrum of a short lever arm for breaking the lip of the bucket out of overlying material when said cradle and bucket are erected from scooping position to carrying position by said cylinder and piston rod unit, said wheels rolling forward on the ground to support said cradle and bucket during the pivotal motion of said cradle on said boom in said erecting movement.

References Cited UNITED STATES PATENTS 2,482,612 9/1949 Drott et al. 214-776 2,773,613 12/1956 Burrus 214-774 2,783,903 3/ 1957 Beyerstedt 214-775 2,835,397 5/1958 Wagner 214774 2,897,987 8/1959 Johansson 214--776 r HUGO O. SCHULZ, Primary Examiner. 

